Drug susceptibility of Mycobacterium tuberculosis isolates from smear negative pulmonary tuberculosis patients, Addis Ababa, Ethiopia

Abstract

Abstract
Drug resistance tuberculosis threatens the National Tuberculosis Control Programme in several countries. A crosssectional
study was conducted during the period between November 2004 and October 2005 to determine drug
susceptibility pattern of Mycobacterium tuberculosis (n=37) isolated from smear negative pulmonary tuberculosis
patients (PTB), and to access whether these patients are at risk of harbouring drug resistant strains. Of the 37 M.
tuberculosis isolates, 21/37 (29.8%) showed resistance to any of the drugs tested. No MDR-TB strains (resistant to
INH and Rifampicin) were observed in this study. No statistically significant differences appeared in the frequency and
pattern of resistance between isolates from smear positive and negative cases. This study provides potentially valuable
information of the value of culture in the diagnosis of smear-negative cases to certain extent in untreated newly
diagnosed PTB patients. Smear negative TB patients can harbor drug resistant strains like their smear positive
counterparts. [Ethiop.J.Health Dev. 2008;22(2):212-215]